Unit Converter — Length, Weight, Volume, Temperature, Time, Speed
Pick a unit type — length, weight, volume, temperature, time, or speed — then convert in either direction. CalcWize uses the standard conversion factors and supports the most-used metric and imperial units for each category.
Common conversions
1 kg = 2.205 lb · 1 m = 3.281 ft · 1 km = 0.621 mi · 1 L = 0.264 US gal · °F = (°C × 9/5) + 32 · 100 km/h = 62.14 mph. CalcWize handles all of these and a lot more — no need to memorise.
Where the imperial / metric split bites
Cooking is the obvious one — a US recipe in cups, ounces, and degrees Fahrenheit translated into European grams, millilitres, and Celsius. Travel is another (signs in km vs. mi, fuel in L vs. gal). DIY (lumber in 2×4 inches vs. millimetres). Shipping (lb vs. kg). The unit converter is at its most useful when you don't fully trust someone else's number and want to see it in your default mental model.
Watch out for US vs. UK gallons
A US gallon (3.785 L) and a UK Imperial gallon (4.546 L) are about 20% different — meaningful when you're reading a fuel-economy spec or a recipe. CalcWize defaults to the US gallon for volume; pick the unit explicitly if you need the Imperial one. For temperature, °C and °F are unambiguous; Kelvin is for scientific contexts.
Frequently asked questions
- Does it use US or UK gallons?
- Volume defaults to the US gallon (3.785 L). The UK imperial gallon (4.546 L) is about 20% larger, so pick the unit explicitly if you need it.
- How precise are the conversions?
- They use internationally agreed standard factors and are accurate for everyday use — cooking, travel, and DIY. For scientific or legal precision, use a specialised reference.
How we calculate it
Each value is converted to a base unit for its category (for example metres for length, grams for mass) and then to the target unit using standard conversion factors. Temperature uses the exact linear formulas, such as °F = °C × 9/5 + 32.
What it doesn't do
- Currency or financial conversions (use the Currency Converter)
- Niche scientific units (μm, parsec, etc.)
Last reviewed: 2026-05